Conventionally, a door lock apparatus includes a latch mechanism, a lever mechanism, a link mechanism, and a motor drive mechanism, or the like, provided in a housing (as disclosed in JP2003-314116A; document 1). The latch mechanism changes a state of the vehicle door to the vehicle body between a state where the vehicle door is retained to be closed and a state where the vehicle door is enabled to open. The lever mechanism is actuated when a door opening means such as a door handle, or the like, is operated, and actuates the latch mechanism. The link mechanism and the motor drive mechanism change the state of the door lock apparatus between an unlocked state where the latch mechanism can be actuated and a locked state where the latch mechanism cannot be actuated. In these mechanisms, because the motor drive mechanism is configured from an electric part, if the motor drive mechanism makes contact with water, the electric part will be short-circuited and the short will cause trouble. Accordingly, some waterproofing measures need to be made for the door lock apparatus.
Document 1 discloses a door lock apparatus including two covers (a first cover and a second cover) configuring a housing for protecting parts inside the housing. An edge of each cover is joined to an edge of other cover. Further, in order for inhibiting water from entering the housing through a joint portion of the first cover and the second cover, a third cover is integrally provided over the first cover. Thus, the joint portion is protected from water entering the housing from upper part of the housing. As described above, in the door lock apparatus disclosed in the document 1, water is inhibited from entering the housing from an upper part of the housing, and the water is inhibited from contacting the electric part.
However, in the door lock apparatus disclosed in the document 1, when an boundary end portion is highest in the third cover, when water reaches the boundary end portion, the water droplet moves and spreads along a peripheral end portion of the third cover, and reaches near the joint portion of the first cover and the second cover. In this case, the third cover cannot sufficiently work any more. Then, there can be a danger that water enters the housing through the joint portion of the first cover and the second cover and induces short-circuit of the electric part, or induces other adverse effects, and causes trouble of the door lock apparatus.
A need thus exists for a door lock apparatus, which can inhibit water from approaching and contacting an electric part in a housing with reliability. The present invention has been made in view of the above circumstances and provides such a door lock apparatus.